int x(int t) {
  if (t & 256)
    return -26;
  return 0;
}

We generate this:

     tst.w   r0, #256
     mvn     r0, #25
     it      eq
     moveq   r0, #0

while gcc generates this:

     ands    r0, r0, #256
     it      ne
     mvnne   r0, #25
     bx      lr

Scandalous really!

During ISel time, we can look for this particular pattern. One where we have a
"MOVCC" that uses the flag off of a CMPZ that itself is comparing an AND
instruction to 0. Something like this (greatly simplified):

  %r0 = ISD::AND ...
  ARMISD::CMPZ %r0, 0         @ sets [CPSR]
  %r0 = ARMISD::MOVCC 0, -26  @ reads [CPSR]

All we have to do is convert the "ISD::AND" into an "ARM::ANDS" that sets [CPSR]
when it's zero. The zero value will all ready be in the %r0 register and we only
need to change it if the AND wasn't zero. Easy!

llvm-svn: 112664

llvm-svn: 112661

llvm-svn: 112657

llvm-svn: 112654

No CCR virtual registers should exist, and %EFLAGS is used in ways that can
surprise RegAllocFast.

llvm-svn: 112650

llvm-svn: 112644

llvm-svn: 112642

determining if they're likely to be in range of the SP when resolving
frame references.

llvm-svn: 112624

the offset is legally encodable, not actually trying to do the encoding.

llvm-svn: 112622

- Convert {0,1} and friends into 0b01, which is identical and more consistent.

llvm-svn: 112593

Use X86ISD::MOVSS and MOVSD to represent the movl mask pattern, also fix the handling of those nodes when seeking for scalars inside vector shuffles

llvm-svn: 112570

llvm-svn: 112568

things we can't handle.

llvm-svn: 112559

scheduling opportunities (extra instruction can go in between
MOVT / MOVW pair removing the stall).

llvm-svn: 112546

is meant to do exactly the same thing. Thanks to Jim Grosbach for pointing this
out! :-)

llvm-svn: 112538

kill flag.

This could cause duplicate kill flags when the same register was used twice in a
continuous sequence of STRs.

There is no small test case. <rdar://problem/8218046>

llvm-svn: 112534

Auto-upgrade the old intrinsic and update tests.

llvm-svn: 112507

Make ARM add rN, sp, #imm instructions rematerializable. That's how the address of locals is calculated, so this should
help relieve register pressure a bit. Recalculating the local address is
almost always going to be better than spilling.

llvm-svn: 112503

operand is killed, add it to the expanded instruction as an implicit kill
operand instead of marking the individual subregs with kill flags.  This
should work better in general and also handles the case for VST3 where one
of the subregs was not referenced in the expanded instruction and so was
not marked killed.

llvm-svn: 112494

optional modified register (instead of reg0). Along with r112461 it will make
sure that the optional define of CPSR is marked as "def" and will thus mark the
instructions using these classes (t2ANDS*) as setting the 's' flag.

llvm-svn: 112462

The IDX was treated as byte index, not element index.

llvm-svn: 112422

llvm-svn: 112421

IR add/sub operations with one or both operands sign- or zero-extended.
Auto-upgrade the old intrinsics.

llvm-svn: 112416

llvm-svn: 112411

- Create T2I_bin_sw_irs to be like T2I_bin_w_irs, but that it sets the S bit.

llvm-svn: 112399

llvm-svn: 112397

llvm-svn: 112395

llvm-svn: 112394

it sets the CPSR register.

llvm-svn: 112393

times.  This patch causes llc and llvm-mc (which both default to
verbose-asm) to print out comments after a few common shuffle 
instructions which indicates the shuffle mask, e.g.:

	insertps	$113, %xmm3, %xmm0     ## xmm0 = zero,xmm0[1,2],xmm3[1]
	unpcklps	%xmm1, %xmm0    ## xmm0 = xmm0[0],xmm1[0],xmm0[1],xmm1[1]
	pshufd	$1, %xmm1, %xmm1        ## xmm1 = xmm1[1,0,0,0]

This is carefully factored to keep the information extraction (of the
shuffle mask) separate from the printing logic.  I plan to move the
extraction part out somewhere else at some point for other parts of
the x86 backend that want to introspect on the behavior of shuffles.

llvm-svn: 112387

insertp[sd] $0, which is a noop.  Before:

_f32:                                   ## @f32
	pshufd	$1, %xmm1, %xmm2
	pshufd	$1, %xmm0, %xmm3
	addss	%xmm2, %xmm3
	addss	%xmm1, %xmm0
                                        ## kill: XMM0<def> XMM0<kill> XMM0<def>
	insertps	$0, %xmm0, %xmm0
	insertps	$16, %xmm3, %xmm0
	ret

after:

_f32:                                   ## @f32
	movdqa	%xmm0, %xmm2
	addss	%xmm1, %xmm2
	pshufd	$1, %xmm1, %xmm1
	pshufd	$1, %xmm0, %xmm3
	addss	%xmm1, %xmm3
	movdqa	%xmm2, %xmm0
	insertps	$16, %xmm3, %xmm0
	ret

The extra movs are due to a random (poor) scheduling decision.

llvm-svn: 112379

when the top elements of a vector are undefined.  This happens all
the time for X86-64 ABI stuff because only the low 2 elements of
a 4 element vector are defined.  For example, on:

_Complex float f32(_Complex float A, _Complex float B) {
  return A+B;
}

We used to produce (with SSE2, SSE4.1+ uses insertps):

_f32:                                   ## @f32
	movdqa	%xmm0, %xmm2
	addss	%xmm1, %xmm2
	pshufd	$16, %xmm2, %xmm2
	pshufd	$1, %xmm1, %xmm1
	pshufd	$1, %xmm0, %xmm0
	addss	%xmm1, %xmm0
	pshufd	$16, %xmm0, %xmm1
	movdqa	%xmm2, %xmm0
	unpcklps	%xmm1, %xmm0
	ret

We now produce:

_f32:                                   ## @f32
	movdqa	%xmm0, %xmm2
	addss	%xmm1, %xmm2
	pshufd	$1, %xmm1, %xmm1
	pshufd	$1, %xmm0, %xmm3
	addss	%xmm1, %xmm3
	movaps	%xmm2, %xmm0
	unpcklps	%xmm3, %xmm0
	ret

This implements rdar://8368414

llvm-svn: 112378

a new EltStride variable instead of reusing NumElems variable
for a non-obvious purpose.  No functionality change.

llvm-svn: 112377

and hasn't kept up with ToT.  Approved by Anton.

llvm-svn: 112375

llvm-svn: 112357

being actively maintained, improved, or extended.

llvm-svn: 112356

Also teach this logic how to handle target specific shuffles if
needed, this is necessary while searching recursively for zeroed
scalar elements in vector shuffle operands.

llvm-svn: 112348

llvm-svn: 112336

the special values that for ARM would be used with IB or DA modes.  Fall
through and consider materializing a new base address is it would be
profitable.

llvm-svn: 112329

all the other LDM/STM instructions.  This fixes asm printer crashes when
compiling with -O0.  I've changed one of the NEON tests (vst3.ll) to run
with -O0 to check this in the future.

Prior to this change VLDM/VSTM used addressing mode #5, but not really.
The offset field was used to hold a count of the number of registers being
loaded or stored, and the AM5 opcode field was expanded to specify the IA
or DB mode, instead of the standard ADD/SUB specifier.  Much of the backend
was not aware of these special cases.  The crashes occured when rewriting
a frameindex caused the AM5 offset field to be changed so that it did not
have a valid submode.  I don't know exactly what changed to expose this now.
Maybe we've never done much with -O0 and NEON.  Regardless, there's no longer
any reason to keep a count of the VLDM/VSTM registers, so we can use
addressing mode #4 and clean things up in a lot of places.

llvm-svn: 112322